<!DOCTYPE html>
<html>

	<head>
		<meta charset="UTF-8">
		<title></title>
	</head>

	<body>
		<!--
			火箭2.0版本(火箭的速度先快后慢,当body的scorllTop距离小于8%时,速度变快,并且火箭最终飞出顶部)
		-->

		<style type="text/css">
			* {
				margin: 0;
				padding: 0;
			}
			
			.web {
				height: 10000px;
				background: linear-gradient(#fff, #000);
			}
			
			.rocket {
				width: 149px;
				height: 249px;
				background: url(../img/rocket_button_up.png) 0% 0%;
				position: fixed;
				top: 420px;
				right: 20px;
			}
			
			.rocket:hover {
				background-position: -100% 0;
			}
			
		</style>
		<div class="web">

		</div>
		<div class="rocket">

		</div>
		<script type="text/javascript">
		</script>
	</body>

</html>